Scanning electron micrograph (SEM) depicting a grouping of Vibrio vulnificus bacteria
The bacterial species Vibrio cholerae
has many different types, or serogroups. Only two of those types have ever caused epidemic cholera: serogroups O1 and O139 (O139 is found only in Asia). Even among those serogroups, strains that lack cholera toxin do not cause cholera. The other serogroups are known collectively as "non O1, non O139 V. cholerae
." Although these can cause diarrheal illness, it is generally mild, compared with the organism that causes the disease cholera, and do not have epidemic potential. These bacteria also rarely can cause wound infections. Diarrheal illness is treated with rehydration. Sepsis or wound infections require antibiotic treatment.
Non-Cholera Vibrio Infections
- Vibrio parahaemolyticus is a bacterium in the same family as those that cause cholera. It lives in brackish saltwater, and causes gastrointestinal illness in humans. V. parahaemolyticus is a halophilic, or salt-requiring organism, naturally inhabiting coastal waters in the United States and Canada, and is present in higher concentrations during summer. When ingested, V. parahaemolyticus causes watery diarrhea often with abdominal cramping, nausea, vomiting fever and chills. Usually these symptoms occur within 24 hours of ingestion. Illness is usually self-limited and lasts 3 days. Severe disease is rare and occurs more commonly in persons with weakened immune systems.
Vibrio vulnificus is a bacterium in the same family as those that cause cholera. It normally lives in warm seawater and is part of a group of vibrios that are called "halophilic" because they require salt. V. vulnificus can cause disease in those who eat contaminated seafood or have an open wound that is exposed to contaminated seawater. Among healthy people, ingestion of V. vulnificus can cause vomiting, diarrhea, and abdominal pain. In immunocompromised persons, particularly those with chronic liver disease, V. vulnificus can infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock), and blistering skin lesions. V. vulnificus bloodstream infections are fatal about 50% of the time.
Useful Vibrio Infection Links